I upgrade to Debian Lenny on my colo box today. It was relatively painless. I had to upgrade php to php5 manually, because the php4-mysql refused to upgrade and refused to re-install. I had to mess around a bit with my Apache config. The biggest pain was dealing with the “4gb seg fixup” errors. In the past, every time libc upgraded I had to remove /lib/tls and then it was done. But this time I had to install libc6-xen, and then edit /etc/ld.so.conf.d/libc-xen.conf to change “hwcap 1 nosegneg” to “hwcap 0 nosegneg” and then run ldconfig and reboot.
Everything appears to be working except the munin plugin for apt is acting a little weird, so I’ll call this done.